Summary Ad valorem taxes are property taxes generally assessed and levied at the local level. Each state usually proscribes the evaluation method, with two major approaches to oil and gas properties being common: basing the assessment on the level of prior production or using a discounted cash flow model to project the future value. Tax rates can vary widely in the local taxing entities, and a county or parish may encompass many different taxing entities. This paper briefly surveys the approaches taken to ad valorem taxation on oil and gas properties in producing states.